This invention relates to an improved one-way clutch and more particularly to an improved, lightweight and low cost one-way clutch.
One-way clutches are utilized for a wide variety of purposes. Such clutches are employed so as to provide unidirectional drive between a driving and a driven member while permitting the driven member to overrun the driving member or to rotate in an opposite direction without interference from the driving member. One form of such clutch employs an annular inner member having a cylindrical outer surface. A caging member encircles the inner member and defines a number of recesses in which individual balls are received. The balls are urged against a wedging surface and into engagement with the cylindrical surface of the inner member so as to provide a driving relationship in one direction while permitting the overrunning or reverse rotation as aforedescribed.
A prior art type of one-way clutch is illustrated in FIGS. 1 and 2 of the drawings and now will be described by reference to those two figures. Such a clutch is indicated generally by the reference numeral 11 and is particularly adapted to transmit a drive to a driven shaft 12 from a driving element, such as a gear 13. The one-way clutch 11 is designed so as to permit drive to be transmitted from the gear 13 to the shaft 12 while permitting the shaft to overrun the gear 13 or to rotate in an opposite direction freely to the gear 13.
The one-way clutch 11 is comprised of a caging member, indicated generally by the reference numeral 14 that defines a plurality of recesses 15 in which rollers 16 are positioned. The rollers 16 are adapted to cooperate with a cylindrical outer surface 18 of an inner member 19 which is fixed for rotation with the gear 13. The inner member 19 and specifically its outer surface 18 is spaced inwardly from a corresponding cylindrical inner surface 21 of the caging member 14. The inner surface 21 is interrupted by the recesses 15.
A plunger 22 is slidably supported in a bore 23 of the caging member 14 adjacent each recess 15. A coil compression spring 24 is received in each of the bores 23 and urges the respective plunger 22 into engagement with the rollers 16. The rollers 16 are, in turn, cammed by the camming surfaces 17 into engagement with the outer surface 18 of the inner member 19.
In the illustrated embodiment, the caging member 14 is connected to a driving plate 25 by means of a plurality of screws 26. The driving plate 25 has a splined connection 27 to the driven shaft 12 so that the caging member 14 will be driven with the driven shaft 12.
The device operates as follows. The gear 13 and inner member 19 are driven in a clockwise direction as viewed in FIG. 2. The combination of the spring biased plungers 22 and the shape of the wedging members 17 causes the rollers 16 to become wedged into engagement with the inner member surface 18 so as to transmit a drive in the same direction, as indicated by the arrow, to the caging member 14 and shaft 12. If, however, the 12 overruns, the rollers 16 will be cammed against the plungers 22 so as to permit the shaft to overrun the inner member 19.
Although this prior art type of one-way clutch has a number of advantages, the caging member must be formed from a very strong material and must have sufficient thickness so as to overcome the large compressive loads exerted by the rollers 16. Thus, it has been impractical, with prior art devices, to provide a lightweight, low cost caging member.
It is, therefore, a principal object of this invention to provide an improved one-way clutch mechanism that permits the use of a lightweight caging member without sacrificing strength.
It is a further object of this invention to provide a caging member that may be formed in convenient manner and yet which will afford high strength.